-
384
Aristotle
Aristotle (384-322 B.C.), a Greek philosopher, had the most sophisticated of all the Greek views regarding spontaneous generation. He believed that there were four elements and a fifth essence, called the “quintessence” or “ether” that occurred only in the heavens, otherwise known as space. There were four terrestrial elements, which included earth, air fire and water. Each element is a principle of hot, cold, dry and wet. Aristotle claimed thought that living organisms were created due to a mix -
Jan 1, 611
Anaximander
Anaximander (611-547 B.C) was a Milesian (Turkish) philosopher. He believed that everything originated from the elemental nature of the universe (wind, earth, fire and water). This belief was called the “aperion” or “unbounded”. He claimed that living creatures start to form in wet environment when the sun was shined on them. -
Jan 1, 1580
Jan Baptist Van Helmont
Jan Baptist Van Helmont (1580-1644), a Flemish chemist, physiologist and physician produced experiments supporting spontaneous generation. He showed that a willow spontaneously generated mass from another source. After five years of growth, the willow tree grew in size, but the soil underneath the tree did not decrease in matter. Furthermore, he also made a recipe for generating mice with soiled cloth and scorpions from basil, bricks and sunlight. -
Francesco Redi
Francesco Redi (1626-1697) was an Italian physician that conducted an experiment in 1668 that disproved the theory that maggots arise from decaying meet. He showed that maggots came from fly larvae laid directly on the meat itself. In his experiment, Redi covered the decaying meet, blocking access to adult flies. In the end, no maggots could be found. This proved that decaying meat alone could not create maggots, but when in contact with adult flies, maggots were created. -
John Needham
John Needham (1713-1781) was an accomplished microscopist who conducted a series of experiments with boiled broths in 1745. It was believed that by boiling a substance, any living organisms would be killed. After boiling the broth and sealing the container for Needham’s experiment, the broth was still cloudy, an indicator of life in the broth. This was a sign that spontaneous generation still occurred after boiling. -
Lazzaro Spallanzani
Lazzaro Spallanzani (1729-1799) was an Italian scientist who modified Needham’s experiment in 1768. He hypothesized that after Needham boiled the broth and placed it into a jar, the broth became contaminated. On the other had, Spallanzani’s method involved boiling the broth in a sealed container with the ability for air to partially evacuate, hence preventing an explosion. This method prevented any growth in the broth. However, spontaneous generation followers stated that Spallanzani only proved -
Charles Cagniard de la Tour and Theodor Schwann
Charles Cagniard de la Tour (1777-1859), a physicist, and Theodor Schwann (1810-1882), one of the founders of cell theory, published their independent discovery of yeast in alcoholic fermentation. When yeast was not present, only sterile air or pure oxygen was present in the substance and fermentation never occurred. This meant that airborne microorganisms, not spontaneous generation, were the cause fermentation. This discovery would later solidify Pasteur’s experiment. -
Louis Pasteur
Louis Pasteur (1822-1895) was a French chemist scientist and inventor. In order to settle the debate on spontaneous generation, he had to make an experiment that showed that a substance can be absent of all life and if properly protected, no living organisms would be become present, even when exposed to air. He first boiled broth in a flask to kill all living organisms. Then he heated the neck of the flask and bent it into an “S” shape, preventing any organisms from reaching the broth, but allow
